This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We have developed a diffusing probe, which can be used in combination with diffuse optical spectroscopic (DOS) methods, to noninvasively determine full spectrum optical properties of superficial in-vivo skin in the wavelength range from 650-1000 nm. This new probe relies on a simple two-layer diffusion model to determine tissue absorption and reduced scattering coefficients.